In the 1938 black and white film Pygamlion, produced by Gabriel Pascal, directed by Leslie Howard and Anthony Asquith, and based on George Bernard Shaw's 1913 Pygmalion, Leslie Howard and Wendy Hiller play the parts of Henry and Eliza. The chemistry between these two unlikely matched characters is easily detected, unlike the Eliza and Henry characters in the George Cukor 1964 musical version My Fair Lady, played by Audrey Hepburn and Rex Harrison.
In the movie Pygmalion, I love the way that Henry's eyes would immediately light up when Eliza would walk into the room. Even with her goofy girlish ways, she seems to capture him from the start. One would not know by the horrendous exercises he puts her through or the way he talks to her, but one can see it in his expressions and actions. Even thought he clearly detests her initial use of phonetics and helps her change the way she talks, it is still the same charm and never-ending personality that he falls in love with and cannot live without. He is even amused with her when they are visiting his mother for the first time trying to see if he can pass her off for a lady in front of his mother's friend. When she begins to tell these outlandish stories about her aunt and how someone had "done the old women in," instead of getting upset as Harrison's Henry did in My Fair Lady," Howard's Henry is seen smiling as if he is amused and smitten with her flower-girlish ways.
The chemistry between these characters pour off of the screen. I believe the fact that they were so much closer to each other in age than Henry and Eliza in My Fair Lady aided in that department. It would have been interesting to have seen Audrey Hepburn and Leslie Howard together as Henry and Eliza, but that is another paper altogether.